Abstract Advances in HIV prevention and treatment such as PrEP, medical male circumcision, and more potent antiretroviral therapies may be primarily biomedical in nature, but they require substantial behavioral considerations for optimal uptake. Moreover, the 2015 White House National HIV/AIDS Strategy specifically identifies screening and treatment of mental health and substance use disorders as critical to reducing disparities, reducing morbidity and mortality associated with HIV, and preventing new HIV infections. Both domestically and globally, mental health has been closely tied to substance use disorders, which impact adherence and retention in care. A combination of behavioral and biomedical expertise, therefore, is required to successfully address the HIV epidemic worldwide, with NIH funding priorities reflecting this need. Emanating from the former Sociobehavioral Prevention Research Core, this newly re-imagined Behavioral Science Core (BSC) consists of diverse, multidisciplinary faculty with relevant expertise in behavioral science who will provide CFAR investigators with critical expertise not currently available locally. The overall goal of the BSC is to catalyze behavioral science research that will contribute to curbing the global HIV epidemic and improve outcomes along the continuum of HIV prevention and care. Specific aims are: 1: Promote and support collaborative, interdisciplinary HIV research that integrates cutting-edge behavioral science by constructing a behavioral science infrastructure within the CFAR that will maintain an online database of CFAR behavioral resources and investigators, organize symposia to promote local and regional cross- disciplinary collaboration, and facilitate coordinated and collaborative responses to relevant funding opportunities; 2: Provide technical assistance related to behavioral science to the diverse community of CFAR investigators, with a particular focus on the development and evaluation of intervention strategies, behavioral theory, and measurement of mental health and substance use; 3: Provide training and assistance in the use of qualitative methods, especially to inform the development and evaluation of behavioral interventions, including a workshop series and a mobile Qualitative Methods Laboratory fully equipped with video- and audio-recording capability for use by CFAR investigators for usability testing, acceptability assessment, cognitive interviewing, focus group sessions, and in-depth qualitative interviews; 4: Provide mentorship, education, and training on behavioral science integration to early- and mid-stage investigators, with a priority on underrepresented racial/ethnic minorities by convening a monthly Junior Investigator Group as well as (in collaboration with Developmental Core) offering consultations for relevant New Investigator Award (NIA) applicants, participating in mock peer reviews, and supporting eligible faculty in applying for training awards and mentoring successfully.